Games are mechanics wearing a setting. An originality check reads the mechanic.
Two games can share a setting and play nothing alike, or share almost no surface detail and be the same game underneath. A useful originality read has to work at the level of the mechanic, which is the same problem as evaluating a product concept.
The closest recorded demonstration is the thank-you note app check. It separated the underlying mechanic - analysing a person's history to generate output matching it - from the application it was dressed in, and found the mechanic was already shipping in Google Smart Compose and in ghostwriting tools. The application was new; the mechanic was not. A game concept gets read the same way.
If a working title collides with an active registered trademark in the same category, that is escalated as a legal matter rather than a creative one, in noticeably stronger language. The Westfield check shows exactly how that escalation reads and how it differs from ordinary similarity.
It will not predict whether a game will find an audience, and it will not evaluate whether the design is fun. It reads the concept for overlap and hands back the gap.